A signal is to be transmitted through a wave of wavelength $$\lambda $$, using a linear antenna. The length l of the antenna and effective power radiated P_eff will be given respectively as :

(K is a constant of proportionality)

A signal of frequency 20 kHz and peak voltage of 5 Volt is used to modulate a carrier wave of frequency 1.2 MHz and peak voltage 25 Volts. Choose the correct statement.

In amplitude modulation, sinusoidal carrier frequency used is denoted by $${\omega _c}$$ and the signal frequency is denoted by $${\omega _m}$$. The bandwidth ($$\Delta {\omega _m}$$) of the signal is such that $$\Delta {\omega _m}$$ < < $$\omega _c$$. Which of the following frequencies is not contained in the modulated wave?

A modulated signal C_m(t) has the form C_m(t) = 30 sin 300 $$\pi $$t + 10 (cos 200 $$\pi $$t −cos 400 $$\pi $$t). The carrier frequency c, the modulating frequency (message frequency) f_{$$\omega $$}, and the modulation index $$\mu $$ are respectively given by :